This invention relates to electron emitters and devices.
Electron emitters are used in various devices, such as, for example, cold cathode or other lamps, or in displays. They produce radiation by direct bombardment of a fluorescent layer or by ionisation of a gas, such as in the manner described in GB 2297862.
One form of electron emitter has p-n heterojunction where, for example, the p-type junction is formed by diamond appropriately doped, such as with boron. Examples of electron-emitting diamond junctions are described in U.S. Pat. No. 5,410,166; U.S. Pat. No. 5,202,571; "Diamond Junction Cold Cathode" by Brandes et al., Diamond and Related Materials 4(1995) 586-590; and "Backward Diode Characteristics of p-Type Diamond/n-Type Silicon Heterojunction Diodes" by Phetchakul et al., Jpn J. Appl. Phys. Vol. 35 (1996) pp. 4247-4252. P-n junction emitters are described in "Negative electron affinity devices" by R. L. Bell, Clarendon Press 1973.